"Boinging" strings

[Delwin D Fandrich]

Glenn wrote:
> 
>  Hello All.
> 
> The piano I restrung (the Vogue baby grand I have talked about here before)
> turned out okay except for the first two notes of wire, just above the bass
> strings.  They have a "boinging" sound.  Since the original scaled called
> for 21 gage I thought perhaps substituting 20 gage (thus adding tension)
> would eliminate that problem.  Another tech friend didn't think it would
> help much.  He blamed poor scale design and poor piano design.
> 
> Well, to my horror, my "new" 1922 Steinway M has a similar sound at C#2
> (first of the wire).  It is no where near as bad as the Vogue but now I am
> listening for it and therefore, I am finding it.  My M is also freshly
> restrung.
> 
> Do you know what I am referring to?  Is there a solution?  Is it because the
> heavier gauge wire has to "settle in?"  PLEASE let that be it!
> 
> I tried voicing on the Vogue.  I stabbed those two hammers so much it looked
> like a recreation of the shower scene in Physco.  Didn't help.  When you go
> up the scale it goes "dah -dah -dah -dah -BOING -BOING -dah -dah"  or
> something like that!!  I could record it and attach it as a file  . . . nah.
> 
> HELP!
> 
> Glenn.
----------

Glen,

The problem you’ve discovered in your Vogue is fundamental to the design
of the instrument. (It will not have been helped by the aging of the
soundboard, but that’s another story.) As you discovered, reducing the
tension of the lowest plain wire unison by 12 to 15 pounds won’t help
the tone. (Switching from #21 to #20 wire would have reduced the
tension, not raised it.) Nor will voicing the hammer to oblivion. The
sound you are hearing is caused only in part by the stringing scale with
the rest coming from the bridge layout on the soundboard and the design
of the soundboard and rib scale.

I have no idea what the stringing scale is like in the Vogue, but in the
Steinway M, C#-29 (the first plain steel unison) has a tension of
approximately 113 pounds. E-32 has a tension of approximately 147
pounds. (These numbers will vary slightly from one piano to the next due
to manufacturing tolerances.) In this case the “J”-hook caused a drop in
tension of approximately 34 pounds just 3 notes further down. Of course
the effect on the character of tone is disastrous. And, as thousands of
technicians have found out on thousands of pianos, no amount of hammer
voicing is going to make it right. (By the way, struggling with this
model repeatedly through the ‘70s was one of the major reasons why I
began a study of piano design that has led me to doing what I am doing
today.) 

Changing the stringing scale of the M to include bi-chord wrapped
strings from B-27 through D-30—i.e., adding two unisons of bi-chord
wrapped strings—will make the acoustic effect of the J-hook less bad.
The rest of the problem comes from the design of the soundboard and rib
set. If you’re not changing that, there’s not much more to be done.
(Actually, with the M there is an alternate approach that does not
require messing with the hitch pins, but this is as close as I’ll get to
giving stringing scale advice without seeing the actual scale lengths
for the specific piano on paper. All stringing scale changes have to be
integrated into the overall stringing scale design. Stringing scales,
like all other aspects of the piano’s design, have to be considered as
part of a unified whole.)

I’ve never discovered a reasonable sounding theoretical basis for the
“J” hook at the low end of the tenor bridge, but it is always a scaling
disaster. Still, it is a feature found in nearly every early scale
regardless of the size of the piano, which is to say it is found in
nearly every piano marketed today. 

( By the way, your friend was right…)

--ddf